Satellites, such as communications satellites, are typically placed in orbit via a multistage launch vehicle. The launch vehicle carries one or perhaps a few satellites to an insertion orbit at which point the satellites separate from the launch vehicle and fly to their final operational orbit.
A great deal of time is spent at the launch site to prepare a satellite for launch. In particular, with current practice, it takes a substantial amount of time to mount and integrate a single satellite into a launch vehicle. And for launches in which the launch vehicle will carry multiple satellites, that already-substantial amount of time is multiplied by the number of satellites that are being launched.
It is expected that satellite constellations having a very large number of satellites (>500 satellites) will be deployed in the future. For such systems to be financially feasible, it will be necessary to launch a relatively large number of satellites (10-100) in a single launch vehicle. Due to the time issue raised above, in addition to any other constraints, new approaches for satellite launch must be developed.